The University of Pennsylvania (Penn) ACTU consists of the main unit located at the Hospital of the University of Pennsylvania (HUP) and a subunit at the Veterans Administration Hospital (VAH) scheduled to open January 1999. This represents a change in the structure of the Penn ACTU since July 1998 when Thomas Jefferson University (TJU) was removed as a subunit. With this reorganization, funding has been redistributed enabling the addition of seven Penn scientists to the core group of investigators consisting of Drs. Friedman (Principal Investigator), MacGregor (Opportunistic Infections), Frank (antiretroviral therapy), Kolson (neuroAIDS/dementia), and Pomerantz (pathogenesis), the last serves as a consultant to our group. The new scientists include Drs. Gross (adherence to therapy), Holmes (quality of life), Rader (metabolic and lipoprotein abnormalities), Kimmel (risk factors for cardiac disease), Weissman (HIV immunology), Grossman (neuroimaging for AIDS dementia) and Jemmott (recruitment and retention of women and minorities). The HIV clinical program at Penn includes 750 patients cared for at HUP, 435 at the VAH, and 250 at Presbyterian Medical Center. Penn ID physicians are primary care providers for the HIV patients, which provides a link between the providers and the clinical research unit housed within the ID division. The demographics of the clinic population match those of the epidemic in Philadelphia; therefore, African Americans, women and IDU subjects (particularly with the addition of the VAH) have ready access to clinical trials. Approximately 60 percent of study patients come from the clinics while 40 percent are referred from physicians practicing throughout the Delaware Valley, enabling many patients to access HIV clinical trials. The investigators have credentials in basic and patient-oriented clinical research.